kernel/process: Use accessors instead of class members for referencing segment array

kernel/thread: Fix potential crashes introduced in 26de4bb5

This amends cases where crashes can occur that were missed due to the
odd way the previous code was set up (using 3DS memory regions that
don't exist).

gl_shader_decompiler: Remove unused variable in GenerateDeclarations()

Using member variables for referencing the segments array increases the
size of the class in memory for little benefit. The same behavior can be
achieved through the use of accessors that just return the relevant
segment.

core/memory: Get rid of 3DS leftovers

gl_shader_manager: Make ProgramManager's GetCurrentProgramStage() a const member function

This variable was being incremented, but we were never actually using
it.

This function doesn't modify class state, so it can be made const.

Removes leftover code from citra that isn't needed.

Added ability to change username & language code in the settings ui. Added IProfile::Get and SET::GetLanguageCode for libnx tests (#851)

 sink_details: std::move std::function instances 

service: Add migration services

math_util: Always initialize members of Rectangle

video_core: Make global EmuWindow instance part of the base renderer …

kernel: Move object class to its own source files

kernel/thread: Minor changes

input_common: minor changes

yuzu: Use Qt 5 signal/slots where applicable

kernel/vm_manager: Minor changes

vfs_vector: Minor changes

gl_shader_manager: Take ShaderSetup instances by const reference in UseProgrammableVertexShader() and UseProgrammableFragmentShader()

Makes the signal/slot connections type-safe instead of string-based.

Avoids unnecessary atomic reference count increments and decrements

hw: Remove unused files

gl_state: Make texture_units a std::array

service/ns: Add missing ns services

service: Add the psc services

Makes our immutable state explicit.

These two variables correspond to address ranges.

Avoids using a u32 to compare against a range of size_t, which can be a
source of warnings. While we're at it, compress a std::tie into a
structured binding.

This function only reads the data being referenced, it doesn't modify
it, so we can turn the reference into a const reference.

This function isn't used outside of this translation unit, so we can
make it internally linked.

This wasn't being used for anything, so it can be removed.

The lambda elements should be taken by const reference here, and we can
move the virtual directory passed to ReplaceFileWithSubdirectory()

Gets rid of the use of a raw C array.